The value added by intelligent wells (I-wells) derives from real-time reservoir and production-performance monitoring together with zonal downhole flow control. Unfortunately, downhole sensors that directly measure the flow rates and phase cuts required for optimal control of the well’s producing zones are not typically installed. This paper describes an “active” monitoring technique that uses a direct search method to optimize the sequence of interval-control-valve (ICV) positions during a routine multirate test in an I-well.

Introduction

I-well completions include both downhole flow-control tools and monitoring sensors. Reservoir inflow is controlled by means of passive devices [inflow-control devices (ICDs)], active valves (ICVs), and self-adjusting devices (autonomous ICDs and autonomous ICVs). Reservoir and well-performance properties should be monitored regularly to support flow-control decisions efficiently. Various physical quantities, including temperature, pressure, flow rate, acoustics, strain, and seismic, are currently measured by electronic, radioactive, and fiber-optic sensors to assist the multiphase-flow rate allocation in I-wells.

Producing from only a single well or zone during a test is a common practice. This delivers a single flow-rate value measured at a particular time. However, this approach is inefficient, resulting in lost production and possible difficulties when trying to restart the closed-in wells or zones. A costly production-logging well intervention is a possible alternative; it does provide an inflow rate and a phase-cut profile, but only at a specific time without the possibility of delivering the current phase cut and production rate continuously.